High iowait on AIX 5.3 server with page in and out

Hi,
I have seen high waitio on one system having 4 logical cpu, at the time of high iowait pages in and out is also zero ,also runqueue not high , memory is more then enough on system . Also i have check no storage disk are getting 100% busy , its hardly <40 % busy all storage disk.
Also checked queue depth of disk its 20 and number of fc card are 2 , with loadbalace using
SDD driver(vpath). Queue on FC card is also always near about zero.

Not getting where to check why wait IO is too high, one strange thing once user cpu utilization is high iowait reduce.

You should get your app guys to probably tune their sql statements. You have a lot of reading going on. This can be caused by full table scans or index scans. From my own experience(10yrs with Oracle), developers don't want to take the time in developing highly efficient code and let these fast IBM servers absorb the inefficiency hit. Or maybe the DBA's to defrag rebuild indexes/tables.

On the hardware/system side, disregarding all other factors and just looking at your post, you need more disks to spread the IO; possibly more adapters; I didn't see you mention that.
You can run filemon to see if the disk IO is random, which will cause higher IO wait than sequential IO. Look at the "seeks:" output, higher % of seeks means random IO.

IO wait goes down when CPU utilization goes up because the CPU has something more to do than sit idle waiting for IO.